------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- S Y S T E M . I N T E R R U P T _ M A N A G E M E N T -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- -- -- -- GNARL is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. -- -- -- -- As a special exception under Section 7 of GPL version 3, you are granted -- -- additional permissions described in the GCC Runtime Library Exception, -- -- version 3.1, as published by the Free Software Foundation. -- -- -- -- You should have received a copy of the GNU General Public License and -- -- a copy of the GCC Runtime Library Exception along with this program; -- -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- -- . -- -- -- -- GNARL was developed by the GNARL team at Florida State University. -- -- Extensive contributions were provided by Ada Core Technologies, Inc. -- -- -- ------------------------------------------------------------------------------ -- This package encapsulates and centralizes information about all uses of -- interrupts (or signals), including the target-dependent mapping of -- interrupts (or signals) to exceptions. -- Unlike the original design, System.Interrupt_Management can only be used -- for tasking systems. -- PLEASE DO NOT put any subprogram declarations with arguments of type -- Interrupt_ID into the visible part of this package. The type Interrupt_ID -- is used to derive the type in Ada.Interrupts, and adding more operations -- to that type would be illegal according to the Ada Reference Manual. This -- is the reason why the signals sets are implemented using visible arrays -- rather than functions. with System.OS_Interface; with Interfaces.C; package System.Interrupt_Management is pragma Preelaborate; type Interrupt_Mask is limited private; type Interrupt_ID is new Interfaces.C.int range 0 .. System.OS_Interface.Max_Interrupt; type Interrupt_Set is array (Interrupt_ID) of Boolean; -- The following objects serve as constants, but are initialized in the -- body to aid portability. This permits us to use more portable names for -- interrupts, where distinct names may map to the same interrupt ID -- value. -- For example, suppose SIGRARE is a signal that is not defined on all -- systems, but is always reserved when it is defined. If we have the -- convention that ID zero is not used for any "real" signals, and SIGRARE -- = 0 when SIGRARE is not one of the locally supported signals, we can -- write: -- Reserved (SIGRARE) := True; -- and the initialization code will be portable. Abort_Task_Interrupt : Interrupt_ID; -- The interrupt that is used to implement task abort if an interrupt is -- used for that purpose. This is one of the reserved interrupts. Keep_Unmasked : Interrupt_Set := (others => False); -- Keep_Unmasked (I) is true iff the interrupt I is one that must that -- must be kept unmasked at all times, except (perhaps) for short critical -- sections. This includes interrupts that are mapped to exceptions (see -- System.Interrupt_Exceptions.Is_Exception), but may also include -- interrupts (e.g. timer) that need to be kept unmasked for other -- reasons. Where interrupts are implemented as OS signals, and signal -- masking is per-task, the interrupt should be unmasked in ALL TASKS. Reserve : Interrupt_Set := (others => False); -- Reserve (I) is true iff the interrupt I is one that cannot be permitted -- to be attached to a user handler. The possible reasons are many. For -- example, it may be mapped to an exception used to implement task abort, -- or used to implement time delays. procedure Initialize; -- Initialize the various variables defined in this package. This procedure -- must be called before accessing any object from this package, and can be -- called multiple times. private type Interrupt_Mask is new System.OS_Interface.sigset_t; -- In some implementations Interrupt_Mask is represented as a linked list procedure Adjust_Context_For_Raise (Signo : System.OS_Interface.Signal; Ucontext : System.Address); pragma Import (C, Adjust_Context_For_Raise, "__gnat_adjust_context_for_raise"); -- Target specific hook performing adjustments to the signal's machine -- context, to be called before an exception may be raised from a signal -- handler. This service is provided by init.c, together with the -- non-tasking signal handler. end System.Interrupt_Management;